文摘
Chondrites, eucrites and Earth carry uniform p-process 174Hf abundances. Ca–Al rich inclusions have variable p-, and r- (or s-) process Hf proportions. Combined Hf and W isotopes in CAIs reflect selective processing of presolar carriers. No need for interaction between supernova ejecta and the nascent solar system. 176Lu–176Hf and 182Hf–182W chronometers are unaffected by heterogeneity in Hf isotopes.